The incidence of colo-rectal cancer is increasing in all Western countries. Three internationally recognized experts (representing 3 different tongues) have consented to answer 11 questions on this subject in English. The moderator has attempted to summarize and comment on the various viewpoints.Question 1: Your patient has a histologically proven sigmoid carcinoma. What further preoperative examinations (IVP., total colonoscopy, etc.) would you perform as a routine?Goligher: In addition to haematology, grouping and cross-matching of blood, estimation of plasma electrolytes and urea, and chest X-ray examination, I would have a routine IVP done to show the function of both kidneys and possibly reveal any involvement of the left ureter. If the lesion in the sigmoid had been detected by sigmoidoscopy without radiological examination, the advisability of a barium enema study or colonoscopy to exclude another carcinoma or associated polyps would warrant consideration. Previously I relied on a meticulous palpation of the entire large bowel at laparotomy to detect any concomitant lesions, but, whilst this is a satisfactory method for diagnosing further carcinomas -present in 2-3 % of all cases ofcolorectal cancer -it is far from reliable in detecting soft benign polyps, which, if widely distributed, might influence the plan of operation. More recently, therefore, I have been ordering routine pre-operative double-contrast barium enema studies. Unfortunately the presence of a constricting carcinoma in the distal bowel has often made thorough preparation difficult and impaired the quality of the results. I must say that so far the yield from such radiological investigation in my experience has not really justified the inconvenience to the patient.Hollender: In the case of a proven sigmoid carcinoma, we perform as a routine an IVP, which seems to us to be a pre-operative examination of high value in that it shows the condition of the left ureter, the kidneys, and the bladder. If the latter is abnormal, we ask for a cystoscopy, but this is rare.